Technical Field
The present invention relates to a zoom lens.
Description of Related Art
A zoom lens consisting of a plurality of lens groups as a high power zoom, is known. Japanese Patent Laid Open Publication No. 2008-241884 or Japanese Patent Laid Open Publication No. 2006-39005 discloses a zoom lens consisting of a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive or negative refractive power, and a fourth lens group having a positive refractive power and a diaphragm.
In recent years, with a miniaturization of a pixel size of an imaging device, it is required to provide a zoom lens capable of suppressing a variation of aberration throughout an entire zoom range and maintaining a high resolution. Further, since sizes of a housing for housing a lens and a camera platform are restricted, it is also required to miniaturize the zoom lens. However, when a total optical length of the zoom lens is set to be short, the power of each lens group becomes large, thus possibly making it difficult to correct the aberration. Thus, it would be difficult to achieve both of obtaining a high optical performance in the entire zoom range at a high zoom ratio, and shortening the total optical length of the zoom lens.
An object of the present invention is to provide a zoom lens capable of achieving both of obtaining a high optical performance in the entire zoom range at a high zoom ratio, and shortening the total optical length of the zoom lens.